base metal
noun
1
: a metal or alloy (such as zinc, lead, or brass) of comparatively low value and relatively inferior in certain properties (such as resistance to corrosion) —opposed to noble metal
2
: the metal to which a coating or plating is applied : the metal existing underneath a coating or plating
3
: the chief constituent of any alloy
4
: the metal composing parts to be welded
Word History
Etymology
base entry 4